Cambodian election front-runner Hun Sen said on Wednesday he was willing to form a coalition with Prince Norodom Ranariddh, the co-premier he ousted a year ago, but if necessary would change the constitution and go it alone.

Hun Sen's ruling Cambodian People's Party appeared headed for a convincing victory in Sunday's general election. The opposition, led by Ranariddh and his FUNCINPEC party, has alleged fraud and said it would boycott the new parliament and organize protests.Hun Sen planned to travel to northern Cambodia on Thursday to meet the country's head of state, Ranariddh's father King Norodom Sihanouk.

He described his visit as a courtesy call, but analysts said the constitutional monarch's endorsement of the election was crucial and that Sihanouk could also play a key role in resolving the looming constitutional deadlock.

Whoever forms Cambodia's next government will need the approval of two-thirds of the new 122-member parliament, a constitutional requirement that virtually assures another coalition.

Official preliminary results are expected Saturday.

Prak Sokhonn, a senior adviser to Hun Sen, said CPP expects to win 65 to 66 National Assembly seats, FUNCINPEC was expected to win 42 or 43 and the rest would go to the Sam Rainsy Party.

The latest unofficial tally from independent poll-watch group COMFREL had CPP winning 40.7 percent of the vote, FUNCINPEC 32.5 percent, the Sam Rainsy Party 14.1 percent and the 36 other parties 12.7 percent.

"That's the reality. Prince Ranariddh has got to do it (agree to a coalition)," said one Cambodian analyst. "I think that's one of the things Hun Sen will bring up when he meets the king - for the king to push Ranariddh to agree to a coalition," he said.

Hun Sen on Wednesday told Cambodian television he would prefer to form a coalition with Ranariddh rather than Sam Rainsy, the other major opposition figure.

"I think we can cooperate with FUNCINPEC," he said. "It would be a good way to establish a coalition. We can solve deadlock. We can't avoid each other.

"FUNCINPEC can join with us," he said. "Or if FUNCINPEC doesn't want to join us we should amend the constitution, 50 percent plus one, so the CPP would have enough votes to form a new government by ourselves."

Hun Sen said a third alternative was for the current government to continue its work. "If the National Assembly . . . can't approve a new government, the old government can continue."